The so-called Australia's Biggest Mental Health Check-In surveyed some 3-thousand-500 employees across a range of industries.
Run by technology company Medibio, it found one third of program participants live with some form of mental illness, with 36 per cent living with depression, 33 per cent with anxiety, and 31 per cent with stress.
Those numbers represent a slight improvement on last year, when 39 per cent, 37 per cent and 33 per cent registered as having depression, anxiety and stress respectively.
The report also found only 17 per cent of participants living with a mental illness were engaged in treatment, and many of them didn't realise they had one.
Check-In creator Peta Slocombe, says early intervention is crucial.
The Check-In synthesised responses in part by analysing heart-rate data with wearable technologies, such as smartwatches, to monitor and store sleep patterns and stress levels.
Ms Slowcombe says using technology provides a customised, real-time understanding of employee mental health.
The Check-In also found anxiety is rising in women compared to men, with the findings reversed when it comes to depression.
It didn't disclose statistics relating to transgender or non-binary-identifying employees.
Engineering firm Jacobs is the first company of its kind to take part in the survey.
Vice-president of the Australia-New Zealand branch, Ross Jones , says the results from his own employees raised eyebrows at the company.
The Check-In found, overall, less than half of all participants are comfortable disclosing a mental health condition to a supervisor.
While Mr Jones says he's proud Jacobs became the first engineering firm to take part in the Check-In, he says the results indicate the company still has some way to go.
Dr Grant Blashki is from mental health organisation Beyond Blue. He says a focus on mental health in the workplace has proven benefits.
Dr Blashki says attitudes towards mental health, and empathy and sympathy towards those struggling with their mental health, have improved in recent years, after some high-profile cases.
